Description of problem:
See: https://bugzilla.redhat.com/show_bug.cgi?id=718322
Basically with this extension installed via yum, if the screen locks for any reason, the next time the user tries to access the overview, that crash will occur.
Version-Release number of selected component (if applicable):
3.6.1-1
How reproducible:
100%
Steps to Reproduce:
1. Install gnome-shell-extension-native-window-placement
2. Lock the screen or suspend or wait for the timeout to lock it
3. Unlock and try to access the overview (by pressing 'Activities' or moving the mouse pointer to the hot corner, or any of the keyboard combinations.
Actual results:
The screen freezes for a few seconds, the shell hangs, then recovers with an abrt alert
Expected results:
The overview shows up as normal
Additional info:
Installing from https://extensions.gnome.org/extension/18/native-window-placement/ fixes this problem. There's some discussion about it in the comments there, and it was fixed, so I'd guess that an update to the fedora package should also fix this.

Package gnome-shell-extensions-3.6.2-1.fc18:
* should fix your issue,
* was pushed to the Fedora 18 testing repository,
* should be available at your local mirror within two days.
Update it with:
# su -c 'yum update --enablerepo=updates-testing gnome-shell-extensions-3.6.2-1.fc18'
as soon as you are able to.
Please go to the following url:
https://admin.fedoraproject.org/updates/FEDORA-2012-21092/gnome-shell-extensions-3.6.2-1.fc18
then log in and leave karma (feedback).